As is known and understood, inverted-V half-rhombic antennas have been considered for use in ground-to-ground communications systems because of their tactical directional antenna capability in the VHF range. In usage where a five port multicoupler is employed in conjunction with five radio equipments, each operating at a different frequency, as much as 200-400 watts of RF power is fed into the antenna input. Under such conditions, approximately half the power has to be dissipated in the antenna termination--and, typically, non-inductive, lumped resistors have been employed. Oil bath arrangements, however, were usually needed for such combinations, in order to dissipate the large amounts of heat generated in their 100-200 watt lumped resistor terminations. The overall termination package (encasing the oil and the resistor) for such high wattage conditions tended to be quite large, fairly heavy (in the order of 10 lbs. and more), cumbersome and quite expensive. At the same time, such power dissipating resistors exhibited a tendency to be somewhat fragile and, mechanically, of limited strength.
Such characteristics led to a restricted use of these highly directional antennas in tactical ground-to-ground communications systems.